Building up two systems for the peanut flattening rolls in the peanut cold rolling process according to SIMULINK, is imitating to solve the radius of the peanut flattening rolls. It includes the deformation resistance system (kf_Subsystem) and the radius of the peanut flattening roll's calculation system (R_Subsystem). These two systems are used to alternately compute the radius of the peanut flattening rolls. What to adopt is the percentage difference between the radius less than 3% and calculation times less than 10 are the termination condition.